在多库项目中处理Android Studio proguard

I have an application that uses an externally referenced library (that is, the directory of the library is in the same level as the application - it is not copied inside the application's folder). The library is referenced by the application and both the library and the application include proguard files. Everything works fine until I build the application. When I built the app, all referenced to the classes defined in the library are not found - I get 'cannot find symbol class ...) errors on all imports of library classes. As I found, this is because when rebuilding the application, proguard obfuscates all classes and variables and therefore the application cannot reference them. I have added the following to my build.gradle file,I have an application that uses an externally r